(北京有色金属研究总院 能源材料与技术研究所,北京 100088)
摘 要: 采用化学镀方法在TiZrNiCo合金颗粒表面包覆上0.4~2 μm厚的Pd膜,并测得不同膜厚的Pd/TiZrNiCo试样在混合气体中的吸氢动力学。结果表明:Pd膜越薄,Pd/TiZrNiCo抗毒化性能及吸氢动力学性能越好,0.4 μm厚Pd膜试样的吸氢量为2 μm厚Pd膜试样的1.6倍。Pd/TiZrNiCo试样吸放氢后粉化,引发Pd膜破裂导致吸氢速率减缓与基体粉化引发吸氢速率加快的两种效果,吸氢量随吸放氢次数的增加而出现波动性的上升回落。根据吸氢机理及毒化机理,提出并采用相应的动力学模型,并对TiZrNiCo吸纯氢及Pd/TiZrNiCo吸氢动力学曲线进行了拟合。
关键字: Pd膜;抗毒化;动力学;循环寿命;动力学模型
(Institute of Energy Materials and Technology, General Research Institute for Non-ferrous Metals,
Beijing 100088, China)
Abstract:Pd membranes with thickness of 0.4-2 μm were deposited on the surface of TiZrNiCo alloy particles by electroless plating method. Hydrogen absorption kinetics of Pd/TiZrNiCo was measured under mixed gas. The results show that, for the Pd/TiZrNiCo, the thinner the Pd membrane, the better the poisoning resistance and hydrogen adsorption kinetic properties. The pulverization of Pd/TiZrNiCo after hydrogen absorption-desorption leads the two results, such as the decrease of hydrogen absorption caused by the Pd membrane rupture and the increase of hydrogen absorption caused by Pd pulverization. Therefore, the hydrogen absorption-desorption repeating leads to the fluctuation of hydrogen absorption quantity of Pb/TiZrNiCo. Kinetic model for hydrogen absorption under pure hydrogen and mixed gas was built based on hydrogen absorption and impurity gas poisoning mechanism. The hydrogen absorption dynamic curves of TiZrNiCo and Pd/TiZrNiCo were fitted.
Key words: Pd membrane; poisoning resistance; kinetics; cycling stability; kinetic model